Cheng, E.; Yang, H.; Sharma, V.; Lagman, M.; Leeser, D.; Suthanthiran, M. Author Information

Suthanthiran, M1; Yang, H1; Sharma, V K.1; Song, P1; Lagman, M1; Chang, C1; Weir, R1; Chang, E1; Luo, G1; Steinman, R M.2 Author Information

Purpose: Lung cancer has a dismal prognosis and comprises 5.5% of post-transplant malignancies. We explored whether rapamycin inhibits the growth and metastatic progression of non-small cell lung cancer (NSCLC).Experimental Design: Murine KLN-205 NSCLC was used as the model tumor in syngeneic DBA/2 mice to explore the effect of rapamycin on tumor growth and metastastic progression. We also examined the effect of rapamycin on cell cycle progression, apoptosis, and proliferation using murine KLN-205 NSCLC cells and human A-549 NSCLC cells as targets. The in vivo and in vitro effects of cyclosporine and those of rapamycin plus cyclosporine were also investigated.Results: Rapamycin but not cyclosporine inhibited tumor growth; s.c. tumor volume was 1290 +/- 173 mm(3) in untreated DBA/2 mice, 246 +/- 80 mm(3) in mice treated with rapamycin, and 1203 +/- 227 mm(3) in mice treated with cyclosporine (P < 0.001). Rapamycin but not cyclosporine prevented the formation of distant metastases; eight of eight untreated mice and four of six mice treated with cyclosporine developed pulmonary metastases whereas only one of six mice treated with rapamycin developed pulmonary metastases (P = 0.003). In vitro, rapamycin induced cell cycle arrest at the G, checkpoint and blocked proliferation of both KLN-205 and A-549 cells but did not induce apoptosis. Cyclosporine did not prevent cell cycle progression and had a minimal antiproliferative effect on KLN-205 and A-549 cells.Conclusions: The immunosuppressive macrolide rapamycin but not cyclosporine prevents the growth and, metastatic progression of NSCLC. A rapamycin-based immunosuppressive regimen may be of value in recipients of allografts.

UNLABELLED:Rapamycin is an effective inhibitor of human renal cancer metastasis.BACKGROUND:Human renal cell cancer (RCC) is common and is 10 to 100 times more frequent in patients with end-stage renal disease (ESRD) and candidates for renal transplantation. Treatment of metastatic RCC is largely ineffective and is further undermined by immunosuppressive therapy in transplant recipients. A treatment regimen that prevents transplant rejection while constraining RCC progression would be of high value.METHODS:We developed a human RCC pulmonary metastasis model using human RCC 786-O as the tumor challenge and the severe combined immunodeficient (SCID) beige mouse as the host. We explored the effect of rapamycin, cyclosporine, or rapamycin plus cyclosporine on the development of pulmonary metastases and survival. The effects of the drugs on tumor cell growth, apoptosis, and expression of vascular endothelial growth factor (VEGF-A) and transforming growth factor beta1 (TGF-beta1) were also investigated.RESULTS:Rapamycin reduced, whereas cyclosporine increased, the number of pulmonary metastases. Rapamycin was effective in cyclosporine-treated mice, and rapamycin or rapamycin plus cyclosporine prolonged survival. Rapamycin growth arrested RCC 786-O at the G1 phase and reduced VEGF-A expression. Immunostaining of lung tissues for von Willebrand factor was minimal and circulating levels of VEGF-A and TGF-beta1 were lower in the rapamycin-treated mice compared to untreated or cyclosporine-treated mice.CONCLUSION:Our findings support the idea that rapamycin may be of value for patients with RCC and that its antitumor efficacy is realized by cell cycle arrest and targeted reduction of VEGF-A and TGF-beta1. A regimen of rapamycin and cyclosporine, demonstrated to be effective in reducing acute rejection of renal allografts, may prevent RCC progression as well, and has the potential to prevent mortality due to RCC in patients with ESRD who have received renal allografts.

Background. Immunosuppressive therapy is a risk factor for the increased incidence and metastatic progression of malignancies in organ graft recipients. Transforming growth factor (TGF)-beta(1) has been associated with tumor invasion and metastasis, and we have implicated cyclosporine-associated TGF-beta(1) hyperexpression in tumor progression in mice.Methods. BALB/c mice or severe combined immunodeficient-beige mice were treated with 2 or 4 mg/kg of tacrolimus, and the effect of treatment on mouse renal cancer cell pulmonary metastasis was investigated. We also determined whether tacrolimus induces TGF-beta(1) expression. Spleens from tacrolimus-treated mice were analyzed for level of expression of TGF-beta(1) mRNA with the use of competitive-quantitative polymerase chain reaction assay, and circulating levels of TGF-beta(1) protein were measured with the use of an enzyme-linked immunosorbent assay.Results. Treatment with tacrolimus resulted in a dose-dependent increase in the number of pulmonary metastases in the BALB/c mice (197+/-16 in untreated mice, 281+/-26 in mice treated with 2 mg/kg of tacrolimus, and 339+/-25 in mice treated with 4 mg/kg of tacrolimus; no treatment vs. 4 mg/kg tacrolimus, Bonferroni's P<0.001) and in the severe combined immunodeficient-beige mice (117+/-18 in untreated mice, 137+/-19 in mice treated with 2 mg/kg of tacrolimus, and 216 29 in mice treated with 4 mg/kg of tacrolimus; no treatment vs. 4 mg/kg tacrolimus, P<0.05). Treatment with 4 mg/kg but not 2 mg/kg of tacrolimus resulted in a significant increase in the levels of expression of TGF-beta(1) mRNA and circulating levels of TGF-beta(1) protein.Conclusions. Tacrolimus has a dose-dependent effect on tumor progression and TGF-beta(1) expression, and tacrolimus-induced TGF-beta(1) overexpression may be a pathogenetic mechanism in tumor progression.

BACKGROUND:Apoptosis is a well-documented pathway for islet cell death. One potential mechanism is overexpression of death-promoting Bax compared with antiapoptotic Bcl-2 in islets. METHODS:We isolated islets from 10 human pancreata and measured the expression of Bax mRNA and Bcl-2 mRNA by real-time quantitative polymerase chain reaction; islet and pancreas expression of Bax, Bcl-2, activated caspase-3, and cleaved poly (ADP-ribose) polymerase were also assessed by immunohistochemistry. Islet cell apoptosis was evaluated by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) assay and by flow cytometry. RESULTS:The mean (+/-SE) level of Bax mRNA was 336+/-79 copies per nanogram of total RNA, and the level of Bcl-2 mRNA was 36+/-10 (P=0.001). A positive correlation existed between islet expression of Bax mRNA and Bcl-2 mRNA (P=0.001). The islet Bax to Bcl-2 ratio was 10.8+/-1.3 and 1.71+/-0.3 for the spleens (P=0.0001). Bax mRNA (P=0.04), but not Bcl-2 mRNA, was expressed at a higher level in islets compared with spleens. Human islets contained large numbers of cells expressing Bax protein, whereas only infrequent islet cells expressed Bcl-2 protein, activated caspase-3, and poly (ADP-ribose) polymerase. The apoptotic index was 5% by TUNEL assay, and the percentage of apoptotic islet cells was 9.7+/-2.5% by flow cytometry. Sections of human pancreas before islet isolation showed islet staining for Bax but not Bcl-2. CONCLUSIONS:Our finding that isolated human islets express Bax at a higher level compared with Bcl-2 suggests a molecular mechanism for islet cell death by apoptosis. We hypothesize that reducing islet expression of Bax, or regulating its activation, will help preserve islet cell mass after islet transplantation.

BACKGROUND:The NF-kappaB/Rel family of transcription factors regulates biologic processes ranging from apoptosis to inflammation and innate immunity. Whether c-Rel, a lymphoid-predominant member of the NF-kappaB/Rel family, is essential for transplantation immunity is not known. METHODS:We explored the role of c-Rel in the anti-allograft repertory using mice with targeted disruption of the c-Rel gene (c-Rel-/-) as recipients of H-2 mismatched islet allografts. Allogeneic DBA/2 (H-2d) islets were transplanted into the renal subcapsular space of diabetic c-Rel-/- C57BL/6 (H-2b) mice or the c-Rel +/+ C57BL/6 wild-type mice. Islet graft survival, cellular traffic into the islet grafts and their phenotype, and intragraft expression of cytokines and cytotoxic attack molecules were determined at the protein (by immunohistochemistry) and mRNA (by real-time quantitative polymerase chain reaction) levels. RESULTS:We found superior islet graft survival in the c-Rel-/- recipients compared to c-Rel+/+ C57BL/6 recipients. Splenocytes from c-Rel-/- mice proliferated poorly compared to splenocytes from the c-Rel+/+ mice on stimulation with anti-CD3 mAbs or Con A. Peri-islet infiltration composed of T lymphocytes and macrophages was found in both c-Rel+/+ recipients and c-Rel-/- recipients, but intra-islet infiltration was observed only in c-Rel+/+ recipients. Immunohistologic and molecular studies showed impaired T helper-type 1 immunity and decreased intragraft expression of cytotoxic attack molecules perforin and granzyme B in c-Rel-/- recipients as compared to wild-type recipients. CONCLUSIONS:Our results demonstrate that c-Rel is essential for robust rejection of islet allografts and support the idea that strategies that impair c-Rel function may be of value for constraining alloimmunity and facilitating survival of allogafts.

Maluccio, Mary1; Konijn, Gunnar1; Lagman, Milagros1; Suthanthiran, Manikkam1 Author Information

815 Malignancy is a common and dreaded complication following organ transplantation and effective treatments are urgently needed. A novel immunostimulatory strategy of considerable potential for the effective treatment of neoplasia is the immunization of tumor-bearing host with dendritic cells (DC) pulsed with tumor cells/peptides. Herein, we determined whether DC, pulsed with renal carcinoma cells, are efficacious in preventing tumor progression in an in-vivo tumor model in mice. In view of our earlier demonstration that anti-CD3 mAbs induce differentiation of alloimmune memory cells to secondary cytotoxic T cells as well as enhance the cytotoxic activity of natural killer cells, we also tested the efficacy of DC, pulsed with tumor cells and displaying anti-CD3 mAbs, in preventing tumor progression. The experimental protocol was as follows: 50,000 viable renal cancer cells were injected into the tail vein of syngeneic BALB/c mice to establish pulmonary metastases. BALB/c DC were isolated from bone-marrow cells and grown in culture medium supplemented with IL-4 and GM-CSF. On day 6, the DC were collected, co-cultured with irradiated renal cancer cells, and then treated with anti-CD3 mAbs. DC, pulsed with renal cancer cells, and conditioned with or without anti-CD3 mAbs, were administered by the subcutaneous route and tested for their ability to reduce the number of renal cell cancer pulmonary metastases. (Table)TableOur studies, in addition to identifying a novel immunoregulatory role for anti-CD3 mAbs, suggest a new immunostimulatory strategy for the treatment of malignancy, a common complication in long-term allograft recipients.

Recent advances in single-cell sequencing hold great potential for exploring biological systems with unprecedented resolution. Sequencing the genome of individual cells can reveal somatic mutations and allows the investigation of clonal dynamics. Single-cell transcriptome sequencing can elucidate the cell type composition of a sample. However, single-cell sequencing comes with major technical challenges and yields complex data output. In this Primer, we provide an overview of available methods and discuss experimental design and single-cell data analysis. We hope that these guidelines will enable a growing number of researchers to leverage the power of single-cell sequencing.

BACKGROUND:Transforming growth factor-beta1 (TGF-beta1) is an immunoregulatory and fibrogenic cytokine. In an earlier in vitro study, we demonstrated that cyclosporine (CsA) increases TGF-beta1 transcription rate in human T lymphocytes. Herein, we explored whether CsA augments the in vivo expression of TGF-beta1 in humans.METHODS:The inherent difficulty in studying the in vivo effect of CsA in humans was circumvented by investigating stable end-stage renal disease patients who were preconditioned with CsA before their living donor renal transplantation. Sera and peripheral blood mononuclear cells were obtained from CsA-preconditioned patients and quantified for TGF-beta1 expression at the mRNA (by competitive polymerase chain reaction) and protein (sandwich enzyme-linked immunosorbent assay) levels.RESULTS:Our studies demonstrated a significant increase in TGF-beta1 expression after CsA therapy. The stimulatory effect was unique to TGF-beta1, and CsA did not increase interleukin (IL)-10, IL-6, IL-2, or tumor necrosis factor-alpha expression.CONCLUSIONS:Our first-time demonstration of a TGF-beta1-selective in vivo stimulatory effect of CsA in humans: (1) advances a TGF-beta1-centered hypothesis for the beneficial (immunosuppression) and detrimental (fibrosis, hypertension) effects of CsA use, and (2) broadens the mechanism of immunosuppressive action of CsA to include heightened expression of an endogenous immunosuppressive cytokine.

Current processing of renal biopsy samples provides limited information about immune mechanisms causing kidney injury and disease activity. We used flow cytometry with transplanted kidney biopsy samples to provide more information on the immune status of the kidney.To enhance the information available from a biopsy, we developed a technique for reducing a fraction of a renal biopsy sample to single cells for multicolor flow cytometry and quantitation of secreted cytokines present within the biopsy sample. As proof of concept, we used our technique with transplant kidney biopsy samples to provide examples of clinically relevant immune information obtainable with cytometry.A ratio of CD8+ to CD4+ lymphocytes greater than or equal to 1.2 in transplanted allografts is associated with rejection, even before it is apparent by microscopy. Elevated numbers of CD45 leukocytes and higher levels of interleukin (IL)−6, IL-8, and IL-10 indicate more severe injury. Antibody binding to renal microvascular endothelial cells can be measured and corresponds to antibody-mediated forms of allograft rejection. Eculizumab binding to endothelial cells suggests complement activation, which may be independent of bound antibody. We compared intrarenal leukocyte subsets and activation states to those of peripheral blood from the same donor at the time of biopsy and found significant differences; thus the need for new techniques to evaluate immune responses within the kidney.Assessment of leukocyte subsets, renal microvascular endothelial properties, and measurement of cytokines within a renal biopsy by flow cytometry enhance understanding of pathogenesis, indicate disease activity, and identify potential targets for therapy.